Motor



Dec. 8, 1942.

A. RAPPL MOTOR Filed Oct. 23, 1941 m T w R Vn m N n Am Patented Dec. 8, 1942 UNITED STATES PATENT OFFICE MOTOR Anton Rappl, Bufialo, N. Y., assignor to Trico Products Corporation, Buffalo, N. Y.

Claims.

The present invention relates to fluid operated motors having parking means for bridging the piston to a predetermined position and holding it in such position when the motor is not operating, such motors being especially adapted to drive devices such as windshield wipers wherein it is desirable to have the wiping element parked to one side of the field of vision when the wiper is not in use.

More particularly the invention relates to motors of the type disclosed in my application Serial No. 337,966 filed May 31, 1940, of which the present case is a continuation-inpart. As is there described, the motor may be provided with an automatic valve for alternately applying differential pressures, such as suction and atmosphere, through passages to opposite sides of the piston chamber; and the passage to one side of the chamber is provided with a valve and pressure responsive means to close it and to apply a pressure to said side of the piston chamber independently of the automatic valve, for parking the piston. By this arrangement only two conduits need be extended from a remote control or parking valve to the motor, while at the same time positive parking action is assured.

According to the present invention the valve may be connected to a piston valve for actuation by the latter, the parking action being effected by withdrawal of fluid around the piston valve.

The present invention further contemplates the provision of a sheet of fiber or similar material as a seat for the valve, the material also serving as a gasket to seal the connection between the motor casing and the cylinder of the pressure responsive valve operating means. A backing member, which may take the form of a washer, is clamped between the cylinder and the valve seat for preventing distortion of the latter due to pressure of the valve thereon. By this arrangement the valve and the operating assembly therefor are rendered completely accessible upon removal of fasteners employed to secure the cylinder to the motor casing, while at the same time an eificient valve seating action is provided.

These and other objects and advantages will become apparent from the following description of the embodiment of the invention shown in the accompanying drawing, wherein:

Fig. 1 is a diagrammatic sectional view through the motor;

Fig. 2 is a fragmentary bottom plan view of the cover of the motor casing;

Fig. 3 is a fragmentary sectional view taken along line 3-3 of Fig. 2; and,

Fig. 4 is a schematic view of a control valve for the motor.

As shown in the drawing, the motor may comprise an arcuate casing body II, a casing cover I2, and a vane piston l3 secured to a rock shaft [4 and adapted for swinging movement in the casing. When in the one terminal posi-' tion in which the motor is intended to park, a seal IE on the piston engages the wall I6 of a well I! formed in the cover l2.

The motor may be provided with a suitable snap action valve, such as a snap action valve actuated by the rock shaft M, for alternately placing the piston chamber of the motor, on

opposite sides of the piston, in communication with atmosphere and a source of operating pressure. The snap action valve means, which is not specifically illustrated, may be of the type 7 ton, while port 2| opens into passage 24 leading to a cylindrical valve chamber 25.

Secured to the casing cover [2 over the valve chamber is a cylinder 26, there being interposed between these parts'a sheet 21 of fiber or other suitable gasket material, provided with an opening 28.

A backing member 29 for sheet 21, in the form of a metal annulus or washer, is seated in a counterbore in the cylinder 26, being held clamped between sheet 21 and the counterbore shoulder of the cylinder. A passage 3| extends from the bottom of the cylinder chamber, through the sheet 2? and through the casing cover 12 into well l1. Movable in the cylinder chamber is a piston valve 32 whose stem 33 extends through the aligned apertures in sheet 21 and backing member 29 and at its lower end has afiixed thereto a valve 34. The latter may be joined to the stem by forming the riveted head 35 on the stem, the head serving to limit opening movement of the valve 34, which, when closed, seats upon sheet 21.

The piston valve 32 may comprise a cup member 36 of leather, fiber, or other suitable flexible material, backed by an expander disc 31 having peripheral spring fingers pressing the rim of the cup member into contact with the cylinder wall,

means may comprise amember 43 having a valve face 44 provided with ports opening into conduits 4| and I9, and a port opening into a conduit 45 leading to a source of suction. A valve slide 46 having a recess 41, is slidable on face 44 to connect conduit 45 to either conduit 4| or conduit l9 and to open the other one of the latter conduits to the atmosphere.

The structure described is especially adapted for operation by a source of pressure less-thanatmospheric, such, for example, as exists in the intake manifold of a vehicle engine, and when connected to such a source the operation is as follows:

When conduit 4| is disconnected from the source and conduit 9 is connected to such source, starting with the parts in the position shown in Fig. 1, atmosphere will enter the right side of the motor chamber through port 22 and passage 23, while air will be withdrawn from the left side of the motor chamber through passage 3|, the cylinder chamber, opening 28, valve chamber 25, passage 24, port 2| and valve l8, to conduit l9. Thereby the piston l3 will be moved to the left, and when it approaches its limit position valve 8 will be snapped over by the automatic valve means, reversing the application of suction and atmosphere to ports 2| and 22, causing the piston to move to the right, and upon approaching limit position in that direction, another reversal of valve |8 will again result in the condition shown in Fig. 1.

During such operation it will be understood that the cylinder chamber beneath piston valve 32 will be subatmospheric, even when port 2| is open to the atmosphere, so that atmospheric pressure prevailing above valve 32 will urge the valve assembly downwardly, holding valve 34 open. Accordingly, during operation the motor will perform substantially as though there were direct communication between port 2| and the left side of the motor chamber.

When the conduit valve means are operated to disconnect conduit |9 from the source of suction and to connect conduit 4| to such source, the motor will quickly park. Suction effective upon piston valve 32 will first raise the valve assembly, closing valve 34 against its seat 21, and thereafter drawing air past the flange of the cup 36, partially evacuating the left side of the motor chamber, while air enters the right side through port 22. The latter will, depending upon the position of valve I8, either be open directly to the atmosphere or may receive air entering from conduit l9 which is now disconnected from the source of suction. During the parking action it will be seen that the unit 32 functions first as a piston and then as a check valve allowing air to by-pass into the conduit 4|.

It will be understood that in the construction illustrated the valve assembly is removable as a unit with the apertured locking member 29 and valve seating sheet member 2'1 upon removal of the cylinder 26. The latter may be held in place by two or more screws 42 which are threaded into the cover l2.

' It will be understood further that the construction shown and described is merely illustrative of the inventive principles involved which may be otherwise embodied without departing from the spirit of the invention or the scope of the appended claims.

What is claimed is:

1. In a fluid pressure motor having a motor chamber and piston means movable therein, a .passage for applying operating pressure to the chamber and a second passage for applying a parking pressure to the chamber, the two passages adapted to be associated with means for selectively rendering either passage operative, automatic valve means for alternately directing the operating pressure from the first passage to the chamber on opposite sides of the piston means, a pressure operated valve adapted to open in response to operating pressure in the second passage to place one side of the chamber:

in communication with said second passage, and a second valve closing upon opening of the pressure operated valve for blocking communication.

between said one side of the chamber and the automatic valve means, said second valve being connected to the pressure operated valve for operation thereby.

2. In a fluid pressure motor having a motor chamber and piston means movable therein, means for alternately applying differential pres--v sures to opposite sides of the chamber and including a passage on one side of the piston means, a normally open valve for closing said passage, a cylinder chamber communicating with said passage between the valve and motor chamher, a second passage selectively operable with the applying means and connecting said cylinder chamber to a source of pressure for parking the motor, and a piston in said cylinder chamber between said passages, said piston being connected to the valve for operating the latter and including a cup packing member adapted to by pass fluid to effect the application of the pressure of said source to said side of the motor chamber.

3. In a suction operated motor having a motor chamber and piston means movable therein, an operating passage and a parking passage adapted to be selectively connected to a source of suction, automatic valve means for alternately connecting the opposite sides of the motor chamber to said operating passage and to the atmosphere, a cylinder communicating at its opposite ends with. the parking passage and one side of the motor chamber, a piston valve in the cylinder and arranged to permit the passage of fluid thereby toward the parking passage, and a valve connected to and operated by said piston valve to close communication between the automatic valve and said one side of the motor chamber when the parking passage is connected to a source of suction.

4. In a suction operated motor having a casing with a motor chamber and piston means movable therein, means including an operating suction conduit and passage leading to each side of the motor chamber for alternately connecting the opposite sides of the motor chamber to a source of suction and to the atmosphere, a cylinder and a piston valve therein, a parking conduit communicating with the cylinder on one side of the piston valve and the cylinder on the other side of the piston valve constituting a part of the passage leading to one side of the motor;

chamber, a valve for closing said passage between the cylinder and the suction conduit, said valve being connected to the piston valve for being closed by the latter when suction is applied to the parking conduit.

5. In a suction operated motor having a oasing with a motor chamber and piston means movable therein, means including an operating suction conduit and passage leading to each side of the motor chamber for alternately connecting the opposite sides of the motor chamber to a source of suction and to the atmosphere, a cylinder and a piston valve therein, a parking conduit communicating with the cylinder on one side of the piston valve and the cylinder on the other side of the piston valve constituting a, part of the passage leading to one side of the motor chamber, a valve for closing said passage between the cylinder and the suction conduit, said valve being connected to the piston valve fo being closed by the latter when suction is applied to the parking conduit, and said piston valve including means for allowing fluid to pass thereabout toward the parking conduit.

6. In a suction operated motor having a casing with a motor chamber and piston means movable therein, means including an operating suction conduit and passage leading to each side of the motor chamber for alternately connecting the opposite sides of the motor chamber to a source of suction and to the atmosphere, a cylinder and a piston valve therein; a parking conduit communicating with the cylinder on one side of the piston valve and the cylinder on the other side of the piston valve constituting a part of the passage leading to one side of the motor chamber, a valve for closing said passage between the cylinder and the suction conduit, said valve being connected to the piston valve for being closed by the latter when suction is applied to the parking conduit, said piston valve including means for allowing fluid to pass thereabout toward the parking conduit, and a gasket between the cylinder and the motor casing providing a seat for said valve.

7. In a suction operated motor having a casing with a motor chamber and piston means movable therein, means including an operating suction conduit and passage leading to each side of the motor chamber for alternately connecting the opposite sides of the motor chamber to a source of suction and to the atmosphere, a cylinder and a piston valve therein, a parking conduit communicating with the cylinder on one side of the piston valve and the cylinder on the other side of the piston valve constituting a part of the passage leading to one side of the motor chamber, a valve for closing'said passage between the cylinder and the suction conduit, said valve being connected to the piston valve for being closed by the latter when suction is applied to the parking conduit, said piston valve including means for allowing fluid to pass thereabout toward the parking conduit, a gasket between the cylinder and the motor casing providing a seat for said valve, and a backing member for the valve seating portion of the gasket disposed between the latter and said cylinder.

8. In a parking valve for a motor having a casing provided with a recess for a valve, a cylinder secured to the casing over the recess and a gasket between the cylinder and easing, said gasket having an aperture therethrough, a piston in the cylinder and a valve in said recess for seating against the gasket to close said aperture, and a member extending through the aperture and connecting the valve to the piston.

9. In a parking valve for a motor having a casing provided with a recess for a valve, a cylinder secured to the casing over the recess and a gasket between the cylinder and casing, said gasket having an aperture therethrough, a piston in the cylinder and a valve in said recess for seating against the gasket to close said aperture, a member extending through the aperture and connecting the valve to the piston, the cylinder having a shoulder adjacent said gasket, and a backing member for the valve seating portion of said gasket confined between said shoulder and a portion of the gasket backed by the casing.

10. In a valve construction, a casing having a recess for a valve, a cylinder secured to the casmember disposed between a portion of the latter backed by th casing and said shoulder, a valve for closing over the aperture of the seating member and having a stem extending through said aperture, and means in the cylinder for engagement with said stem.

NTON RAPPL. 

